The length of time before a type of electric generator breaks down is normally distributed with a mean of 71 months and a standard deviation of 2.5 months. What percent of the generators will break down before 66 months?

16%

2.5%

34%

5%

Question

The length of time before a type of electric generator breaks down is normally distributed with a mean of 71 months and a standard deviation of 2.5 months. What percent of the generators will break down before 66 months?

16%

2.5%

34%

5%

Ultrilliam · Answer

Looks like this question was asked before, questioncove.com/updates/580d0f2ce4b05a233fe8bd98 Does this help at all?

Ultrilliam · Answer

Welcome to QC!

Vocaloid · Answer

calculate the z-score

(desired value - mean)/standard deviation

then use a z-table to find the corresponding probability